Tool for shaving down local protuberances



Dec. 11, 1951 J, PLESTER I 2,578,371 i TOOL FOR SHAVING DOWN LOCAL PROTUBERANCES A darf/w @fare-e MMM DCC- 11, 1951 J. PLEs'rER 2,578,371

' TooL FOR sHAvING DOWN LOCAL PROTUBERANCES Filed Feb. 6, 1948 f 2 SHEETS--SHEET 2 Fna. FIG. 5.

' Inventor JOIEP/r 1Q 575e A horney?? Patented Dec. 11, 1951 TOOL FOR SHAVING DOWN LOCAL Y PROTUBERANCES Joseph Plester,Coventry, England, assignor to Sir W. G. Armstrong Whitworth Aircraft Limited, aginton, Coventry, England Application Februaryt, 1948, Serial No.6,756 In Great Britain June' 23, 1947 1 Claim.

This invention relates to a tool for shavingfk down local protuberances from a generally flat surfacefor example, for shaving down the heads of rivets, in an aerofoil surface, which are countersunk and are intended to be flush fitted or proud to an extent of only a few thousandths of an inch.

British Patent Specification No. 571,130 discloses a tool which is very satisfactory for this purpose, but at times there are difiiculties in maintaining the tool in a stable position during the shaving operation.

The main object of the present invention is to provide a satisfactory tool which will be very stable in use.

According to the invention, the tool body has a hollow operative end terminating with a fiat extremity to which extends the end of a rotary face milling cutter disposed within the operative end, and the tool carries a pair of parallel wheels or the equivalent support which, with the said extremity, jointly provide a three point support for the tool on the generally fiat surface with the extremity (and the face of the cutter) substantially fully in contact therewith. In addition, the flat extremity has a recess through which the protuberances can pass (to be engaged by the cutter) as the tool is traversed over the generally flat surface.

In the accompanying drawings: i

Figure 1 is a side elevation of a tool according to the invention;

Figure 2 is a fragmentary rear elevation of the operative end of the tool, showing the wheel support;

Figure 3 is a longitudinal section of the operative end, and Figure 4 an underside plan thereof showing also one form of rotary milling cutter therein; and

Figures 5 to 8 show a preferred form of operative end for the tool, Figure 5 being a side eleva tion, Figure 6 a longitudinal section, and Figures 7 and 8 a top and underside plan, respectively.

Figures 1 to 4 show a tool Ybody II having screwed into it an operativeV end I2 which is locked in position by means of a nut I3. Secured to the other end of the body is a pneumatic motor I4 having an inlet pipe I5 and an exhaust pipe I6, the motor driving a rotary face milling cutter I1 which extends along the hollow interior of the operative end I2 as far as the flat extremity I8 thereof. The extremity has in it a recess (for ex-l ample, as shown at I9) through which the protuberances to be shaved can pass to engage the milling cutter when thetool is moved along the generally flat surface with the dat extremity I8 substantially in full contact therewith. The extremity has, in addition, a second recess 2| diametrically-opposite the first, and in the present instance the exhaust pipe I6 is connected by a connection 22 to a curved pipe 23 the lower end 24 of which directs the exhaust through the recesses 2|, I9 to blow 01T swarf, shavings and the like.

In order to render the tool stable during the shaving operation there is mounted round the operative end I2 of the tool a bracket 26 which may be secured in position by means of a bolt 21 and which carries the spindles 28, 28 of forks 29, 29 in which wheels 38, 30 are journalled. The spindles 28, 28 are, it will be observed, adjustable within the bracket 26 independently of one another, lock nuts 3l being provided for securing them in an adjusted position, and the bracket 26 can be adjusted as a whole, for setting purposes, by means of a bolt 32 carried thereby and adapted to bear on the lower edge 33 of the body II.

Independent adjustment of the spindles 28, 28 allows of setting the tool for use on a curved or other non-planar aerofoil or like surface when this should be necessary. The spindles are held against turning in the bracket 26 by means of cross-pins 35 engaged with vertical slots 36 in the brackets.

In Figures 5 to 8 the fiat extremity I8 of the operative end I2 of the tool is elongated somewhat in the direction of travel of the tool, to provide a firmer support for the tool on the surface over which the tool is to be traversed. In fact, the said extremity is comprised of the ends to two side cheeks 38, 38 spaced from one another to provide the fore-and-aft recesses I9, 2|, respectively.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

A tool for shaving down local protuberances on a generally fiat surface comprising a body, a motor supported by said body, a tubular surface contacting member supported by said body, a rotary face milling cutter driven by said motor and being within said surface contacting member, the latter surrounding said cutter, being of an internal diameter substantially that .of a protuberance and terminating with a flat extremity which is substantially co-planar with said cutter, a bracket carried by said surface contacting member intermediate the ends thereof, and a pair of spaced coaxial wheels carried by said bracket for jointly providing with the flat extremity of said surface contacting member a three point support iorthe tool when on the generally flat surface with the flat extremity of said surface contacting member and said cutter substantially fully in contact therewith, said surface contacting member having its flat contacting extremity relieved on a line bisecting said wheels through which protuberances can pass and be guided for engagement by said cutter as the tool is traversed over the generally flat surface.

JOSEPH PLESTER.

REFERENCES CITED UNITED STATES PATENTS Name Date Nellis May 9, 1893 Number 4 Number Name Date 1,102,856 Berg July 7, 1914 1,195,555 Campbell Aug. 22, 1916 1,924,582 Wineman Aug. 29, 1933 2,242,229 Burleigh May 20, 1941 2,282,397 Deck May 12, 1942 2,393,463 Gottlieb Jan. 22, 1946 FOREIGN PATENTS Number Country Date 382,175 Great Britain Oct. 20, 1932 542,374 France Aug. 10, 1922 571,130 Great Britain Aug. 8, 1945 OTHER REFERENCES Publication, page 170 of March 1945 Aviation" Magazine. 

